1. Field of the Invention
The present invention relates to apparatus for manufacturing semiconductor device and the semiconductor device.
2. Description of the Related Art
An example of semiconductor device includes a base plate, an insulating substrate joined to the base plate, a semiconductor element joined to the insulating substrate, and an external terminal joined to the insulating substrate. The insulating substrate consists of an insulator plate laminated on one side thereof with a metal plate and on the other side thereof with a circuit board. The semiconductor element and the external terminal are joined to the circuit board of the insulating substrate.
Soldering has been in most use as joining means for joining an external terminal to a circuit board of insulating substrate electrically and mechanically. In recent years, research and development is advanced on utilizing ultrasonic-joining instead of solder-joining. Ultrasonic joining is a method for directly joining an external terminal to a circuit board via no joint material such as solder, by pressing the external terminal toward the circuit board of insulating substrate while applying ultrasonic vibration thereto. Ultrasonic joining has some advantages that the joining can be performed at the normal temperature and high joining reliability is obtained between the external terminals and the insulating substrate.
The followings are disclosed with respect to conventional ultrasonic-joining apparatus and joining method. Japanese Unexamined Patent Application Publication No. 2006-128486 (“Patent Document 1”) discloses ultrasonic-mounting method that a semiconductor chip is applied with ultrasonic vibration and flip-chip connected onto a circuit substrate having electrode terminals. Method of Patent Document 1 indicates a way of pressing down by means of substrate pressing tool. However, the method is not a technology for joining structural members of power semiconductor module and the substrate cannot be quite fixed only by pressing down the substrate, and then it is possible that joining state is not stable.
Also, Japanese Unexamined Patent Application Publication No. 2007-123937 (“Patent Document 2”) discloses ultrasonic-joining method and apparatus to hold both sides of joint member between applied member and elastic member and to apply ultrasonic vibration thereto. However, these component members cannot be quite fixed even by holding them by using the elastic member, and then it is possible that joining state is not stable.
Further, WO2005/117095 (“Patent Document 3”) discloses ultrasonic-joining tool to suck connection straps for ultrasonic-connecting connection straps with electrodes and terminals of semiconductor chip. However, these component members cannot be quite fixed only by sucking the members, and then it is possible that joining state is not stable.
In addition, Japanese Unexamined Patent Application Publication No. H10-296985 (“Patent Document 4”) discloses positioning method to make components sucked into a recess part in nearly hip-roofed shape and to micro-vibrate them in the horizontal direction, when positioning components for component-mounting with adhesive agent. However, it is difficult that the method of Patent Document 4 is entirely applied to ultrasonic-joining of component members composing power semiconductor module.
Further, Japanese Unexamined Patent Application Publication No. 2013-158858 (“Patent Document 5”) discloses a tool that spring pins are penetrated through a plurality of through holes for the purpose of positioning of a plurality of plate members. However, if the tool is applied to ultrasonic-joining, the members cannot be quite fixed because of the occurrence of rattling during joining due to clearance for inserting the through holes, and then it is possible that joining state is not stable.